Question

13. Find the roots of the quadratic equation by using the quadratic formula and factorization method (i) x 2 – + 10 = 0

Answer 1

x = 5 or -2

Explanation:

The general quadratic formula is expressed as;

ax²+bx+c = 0

Given

x² - 3x -10 = 0

a = 1, b = -3 and c = -10

x = -(-3)±√(-3)²-4(1)(-10)/2(1)

x = 3±√9+40/2

x = 3±√49/2

x = 3±7/2

x = 3+7/2 or 3-7/2

x = 10/2 or -4/2

x = 5 or -2

By Factorization

x² - 3x -10 = 0

x² - 5x+2x -10 = 0

x(x-5)+2(x-5) = 0

(x-5)(x+2) =0

x - 5 =0 and x+2 = 0

x = 5 or -2